by Geir Mjosund 16/12/2014
How are your navigation skills? Studies in the mountains shows that almost everyone has a map and compass in the backpack, but only about half can actually use the tools to take out a course.
If you learn to use a map and compass properly, the winter trip will be much safer and easier.
Navigation in the mountains – with map and compass
To navigate in the mountains is different than navigating on a summer hiking. Snow can hide creeks, trails and roads, while it may also create its own separate elevations. The snow also makes it impossible to distinguish small lakes, marshes and plains apart. If you are on the white mountain plateau and experience driving snow or fog, the visibility can be as good as gone, and the term white-out will get some content. In the winter the wind varies more than the summer, depending on whether it is a headwind or tailwind, uphill, flat or downhill and not least by how the conditions are excellent (and wax sitting). Therefore, it is difficult to calculate time and distance.
The map shows us the terrain as seen from above. On every map there is drawn a grid that is absolutely necessary to obtain the correct scale and a position indication. The grid refers to earth using latitude and longitude, and it may be more accurate divided into a UTM grid. For GPS users the coordinates in UTM grid tells you where you are.
Height Differences in terrain on shows on the map. Using contour lines we can see roughly how hillock, mountains and peaks are in reality. Equidistance tells us how many meters there are between contour lines. 20 meters is the most common on hiking maps.
Preparations for a trip is half the fun. Much of this consists in studying maps of the area the hike goes through, pointing out possible routes and places you will experience. Not only is it fun to carefully reading map in advance, you are simultaneously familiar with the terrain, which can make the trip easier and reduce hazards.
For trips in the winter you should select map in a scale of 1:50 000, even if you only go after a marked route. Before the trip, you should check what year map was drawn. Older maps often lack important information such as new bridges, huts, roads, reindeer fences, dammed water and the like, but the terrain is quite well reproduced. The main thing is that the map is with you and is frequently used on the hike. To preserve the map in the best possible way you can cover them with transparent contact paper, or smear them with some Vaseline.
It is advisable to draw the route to go before the trip starts. But do not plan the route to detailed, such as determining a certain number of kilometers to be covered each day in a week. Such schedules will often crack down due to bad weather, heavy lead, or perhaps your shape is not as good as you thought. Or you can simply fancy to choose a different route than planned. Plan shorter day walks, often with a rest day or two and take into account that your buddies will go at a different speed than you. It is important to discuss this in advance, so that no conflicts arise along the way.
The more experience you have from drawing routes in unfamiliar areas, the easier it will be to choose the easiest route based on the information the map provides.
- Follow the ridge, be confident, is the simplest advice for safe travel in the mountains. Not only are you safe of an avalanche on ridges, often it is easier to go on the ridges because of snow blowing off.
- Through areas of vegetation, it may be wise to choose hollows or creeks. But do not select stream valleys where the sides are more than two or three meters high. They are prone to avalanches.
- It may be smart to maintain altitude and walk around a valley, instead choosing the shortest path on the map: zipping down the valley and then struggle up on the other side.
- The snow around a water is often hard and easy to walk on and easier to move around than the slippery ice.
Going over rivers and lakes requires extra caution. If the route are alternately on and along a river you need to pay attention in relation to narrow portions. Here the power of the stream will often be so hard that the ice is not strong enough. Nevertheless, it may lie a coating of snow over the water, so the route looks navigable, but do not be fooled!
Before you cross water you should note where outlet and all inflow is so that you steer clear of these parties where the ice is also uncertain. Narrow straits and hidden, shallow areas with more power also uncertain ice.
A dash above the outlet means a dam and shows that the water is regulated. Newer hiking maps has its own darker bluish on regulated water. On other maps you can find two altitude indications (eg. 1091-1078). Although it has been 25 degrees below zero in a month, the ice may be very unsure on regulated lakes, because the water level can constantly vary by several meters.
If the trip goes into unknown territory and particularly when visibility is poor a compass should be actively used. A regular compass consists of a compass housing and a magnetic needle. Some versions also have a mirror. A mirror compass can aim into landmarks more accurately than you can with a regular compass.
The round compass housing is divided into degrees, either 400 degrees or 360. The trip is less complicated if everyone in your party has equal measure division on the compass. At least one must be aware of, and correct for unequal division.
The compass needle points to the magnetic North Pole, if you come near magnetic things can hook pointing errors. Watch out for: iron and ferrous mountains and marshes, radios, electronic equipment and batteries, high voltage pylons and lines.
When taking out a course, do the following:
- Find out where you are on the map, and where you’re going.
- Use the edge of the compass on the map so that it goes in a straight line from where you are to where you’re going. Marching direction arrow must point the way you should. Be precise!
- Turn the compass housing so that the guides at the bottom of the house is parallel with north-south lines on the map.
Now the course is taken out. When you go after the compass, take it away from map. Hold it horizontally with the back towards the belly. Turn you and compass so that the needle going in parallel with the help hook the bottom. The red end pointing toward the north. Your goal is in the direction where the arrow is pointing. Before you start to go, it is wise to remember index number. Pick out a natural point marching direction arrow pointing towards such a stone or similar. Go there, take out the compass, check that the grading has not twisted, select a new landmark, go there, and so on. In poor visibility, it is only a few minutes between each time you use the compass, other times maybe a half hour.
Mountain Navigation without landmarks requires that you are extra careful. Turn to see if your own track revolves much left or right. The rear person can also comment on this.
Keep an eye on the sun. It is a good point to follow, but do not forget that it moves.The wind direction can also help you, but it requires that it remains stable, and it is not so easy to determine.
The compass needle points to the magnetic north pole, while the map grid is often oriented towards the geographical North Pole. Declination is the difference between the magnetic pole and the maps grid. One degree declination means you get about 15 meters off course for every mile you go. In Norway the declination is greatest in eastern Finnmark, with up to eleven degrees. Many places it is so small that you do not need to pay attention to it. At the bottom of the maps it says how great the declination is in degrees.
If you go by the compass in an area with great variation, correct not to get off course. Is the declination ten degrees, you will miss the target by 900 meters if the route is six kilometers. With a declination compass you can easily set how many degrees the declination is. On a standard compass, rotate the compass housing so that you add the number of degrees declination, if the declination is western. Is declination easterly, deduct.
If you do not know where you are, you can make a so-called cross-bearing. This presupposes that you can recognize at least two landmarks. So visibility must be good. Determine the advancing direction against the one landmark. Add edge of the compass lines on a landmark on the map with compass house behind the body. Turn the compass north lines in the house so it match those on the map. Draw a line along the compass line. Perform the same operation with the landmark number two. You are at the intersection between the two position lines. With several landmarks the cross bearing are more precise.
Alongside a map and compass both a clock and an altimeter can be useful aids during the navigation. Make it a rule to remember what time it was when you started. If you know the cruising speed, you will be able to determine approximately where you are as you go. Or at least make up a mind about how far you’ve gone.
An altimeter measures altitude using air pressure and must be adjusted / controlled every time you come to a place with accurate height guide (peak or water). The altimeter is affected by the weather and if you correct the meter at least every four hours, it is very precise. One can go on compass heading until it reaches a certain height and then change course. Or you can follow a hill until you reach a familiar formation, a water or similar.
Make it like a routine to read the map after today hike. Think back on the landscape you walked in while viewing the map. Note the mountain tag you used as a landmark, is marked in the form of contour lines. Take note that you needed extra amount of time through a belt of scrub that does not seem on the map. Check how much height you have won during the day. In this way you get better training in reading maps and will be better able to assess the route in the terrain before the next leg, or the next trip.
If you have any questions, do not hesitate to contact me or use the comment field below.
Have a great hike in the mountains,
16/12/2014 / mountains / 8000ers / map and compass / mtxplore.com